MYCN and neoplasm: The aforementioned polycistronic miR-17 ~ 92 cluster is also transcriptionally activated by MYCN [71, 76] which, at least in part, promotes NB tumourigenesis through miR-17-mediated suppression of p21, a key target of the TGF-β signalling pathway and well established tumour suppressor on account of its role in suppressing cell cycle progression [76].